JP7577752B2 - Circular hosiery knitting machine for producing tubular products - Google Patents

Description

The present invention relates to a circular hosiery knitting machine for producing tubular products.

In particular, the manufactured tubular product is configured to be transferred to a station for sawing or looping to close one of the axial ends of the tubular product.

In the field of manufacturing knitted products using circular knitting machines for hosiery and the like, it is sometimes necessary to transfer the product from the knitting machine used to manufacture the product to another manufacturing unit in order to perform further operations on the product that cannot be performed on the knitting machine or that are not economically expedient to perform on the knitting machine.

In particular in the field of hosiery production, techniques have been developed in recent years for automatically closing the toe of a hosiery product by sewing or looping. Some of these techniques are based on removing the product from the knitting machine used to produce it and transferring it to a station for further processing away from the producing knitting machine, so that the toe of the hosiery product is closed at the station for further processing, while the knitting machine is used to produce another hosiery product. These techniques have the advantage that the productivity of the knitting machine is not significantly disadvantaged over other techniques based on directly closing the toe of the hosiery product on the knitting machine used to produce the hosiery product.

The transfer of a hosiery product, or more generally a tubular product, from a knitting machine used to manufacture such a product to a station where the axial ends of the product are closed, or more generally further operations are performed on the product, is typically accomplished by a removal device which individually engages and removes the knitted loops of the product from the needles of the knitting machine by means of removal elements, and which retains these knitted loops during transfer of the product.

In some techniques for closing the toe of hosiery products, the take-off device is further used to support the product while further operations are performed, while in other techniques, when the take-off device reaches the station where the further operations are performed, it transfers the knitting loops, already removed from the needles, to another device, e.g. a processing device, which has the function of supporting the product while the further operations are performed, so that the take-off device is only used to transfer the product.

Such a processing device positions the loops belonging to one half of the knitted row received from the take-out device so that the loops belonging to the one half of the knitted row are opposite the loops belonging to the other half of the same knitted row, and supports the two partial knitted rows in opposing positions during the intervention of a sewing head or looping head that joins the opposing pairs of knitted loops.

In some known types of take-off devices used simply to transfer the product from the knitting machine that produces it to a processing device, the coupling of the take-off member with the needle for transferring the knitted loop from the needle to the take-off member is usually performed by inserting the head of the needle into a seat formed at the end of the take-off member. For this purpose, the take-off device usually has an annular take-off body, which is arranged coaxially opposite the end of the needle cylinder from which the heads of the needles protrude and which supports a number of take-off members oriented parallel to the axis of the take-off body.

A removal device of this type is described, for example, in EP 0 942 086 A1.

Further known is a take-off device, for example as described in EP 2 250 306 A1, which comprises an annular take-off body supporting take-off members which are radially slidable relative to the take-off body. The take-off body is arranged coaxially around the needle cylinder of the circular knitting machine, so that each of the take-off members is arranged laterally opposite a corresponding needle of the circular knitting machine.

At the station for further operation, a processing device is provided with an annular body arranged with its axis vertical. The annular body has a plurality of spikes on its underside, the spikes being arranged along an imaginary cylindrical surface with an axis coinciding with said axis and extending parallel to said axis. The spikes are arranged uniformly at angular intervals from one another about the axis according to angular intervals corresponding to the intervals between the pick-up members of the pick-up device. In fact, each pick-up member coincides with a spike of the processing device, and when the pick-up device is placed at the station for further operation, the pick-up body of the pick-up device is in a coaxial position with respect to the body of the processing device, the pick-up members are arranged around the annularly arranged spikes, i.e. the annular portion, and each pick-up member is radially aligned with a spike.

When transferring the knitted loop from the needle to the gripping member of the transfer member, it appears that the needle may move the knitted loop along with the needle while the needle is held in a stationary position or as the needle moves relative to the knitted loop.

Known knitting machines arrange a tubular body (also known as a goblet) within and coaxial with the needle cylinder, which is configured to receive the product during its formation.

It is preferable that the upper end of the tubular body widens like an inverted cone.

The tubular body projects from the needle cylinder in a lower region and can be connected to a suction device in a manner known per se for removing the product during its formation.

The tubular body is supported by a support structure of the knitting machine so that it can slide along an axis that coincides with the axis of the needle cylinder, and actuation means are provided that act on the tubular body in a command manner to move the tubular body axially relative to the needle cylinder.

The tubular body is in particular movable on command along an axis coinciding with the axis of the needle cylinder from an inoperative position in which the upper end of the tubular body is located at the same level or at a lower level relative to the upper end of the needle cylinder, to at least one operative position in which the upper end of the tubular body protrudes beyond the upper end of the needle cylinder.

In currently known solutions, the actuating means acting on the tubular body in order to move it axially from a non-operated position to one or more operating positions are advantageously constituted by at least one fluid-operated cylinder having a vertical axis, the fluid-operated cylinder acting with its piston axis on a flange attached to the support element and integral with the tubular body.

However, although the above solutions are widely used, they have drawbacks.

In particular, because movement of the tubular body by the fluid-operated cylinder causes the product to rise along the needle very quickly, some operating methods do not allow perfect alignment of the needle and loop in preparation for transfer, resulting in defects in the product.

In particular, the very rapid rise of the product can, in some cases and with certain types of yarn, result in incorrect mutual alignment of the loops and the transport members, which in fact impairs the transport of the product.

The intent of the present invention is to provide a circular hosiery knitting machine for producing tubular products that can improve upon the background art in one or more of the above-mentioned aspects.

Within this spirit, the object of the present invention is to provide a circular hosiery knitting machine for producing tubular products, which makes it possible to manage the rise of the tubular body depending on the type of product and the yarn used.

Another object of the present invention is to provide a circular hosiery knitting machine for producing tubular products that is highly reliable, relatively easy to provide, and competitively priced.

This aim, as well as these and other objects that will become more apparent hereinafter, are achieved by a circular hosiery knitting machine for producing tubular products according to claim 1, optionally having one or more of the features of the dependent claims.

Further features and advantages of the present invention will become more apparent from the description of preferred, but not exclusive, embodiments of a circular hosiery knitting machine for producing tubular products according to the present invention, shown in the accompanying drawings, which are non-limiting examples.

1 is a schematic axial cross-sectional view showing a tubular body and an actuating means of a knitting machine according to the present invention. FIG. 2 is a side view showing the knitting machine of FIG. 1 . 2 is an enlarged detail view of the upper end of the needle cylinder of the knitting machine according to the invention in an operating state; FIG. FIG. 4 is the same detail as FIG. 3 in another operating state; FIG. 4 is the same detail as FIG. 3 in another operating state; FIG. 4 is the same detail as FIG. 3 in another operating state;

With reference to the drawings, the knitting machine according to the invention, generally designated by the reference number 1, comprises, in a manner known per se, a needle cylinder 2 operable in rotation about a vertical axis 2a, the skirt of which is provided with a number of axial grooves 3, each accommodating a needle 4 operable along the corresponding axial groove 3 to produce a knitted article.

A tubular body 5 is provided inside or coaxially with the needle cylinder 2 and configured to receive the product 40 during its formation.

It is preferable that the upper end of the tubular body 5 widens like an inverted cone.

The tubular body 5 protrudes from the needle cylinder 2 in the lower region and can be connected to a suction device, known per se, for removing the product 40 during its formation.

The tubular body 5 is supported by the support structure of the knitting machine so as to be slidable along an axis coinciding with the axis 2a, and a first actuating means 10 is provided which acts on the tubular body 5 in command to move the tubular body 5 axially relative to the needle cylinder 2.

The tubular body 5 is commandably movable along an axis coinciding with the axis 2a relative to the needle cylinder 2 from an inoperative position in which the upper end of the tubular body 5 is located at the same level or at a lower level relative to the upper end of the needle cylinder 2, as shown in FIG. 3, to at least one operative position in which the upper end of the tubular body protrudes beyond the upper end of the needle cylinder 2, as shown in FIGS. 4, 5 and 6.

The tubular body 5 is preferably movable on command from a non-operating position to a number of operating positions in which the upper end of the tubular body protrudes to different extents from the upper end of the needle cylinder.

As an example, Figure 4 shows a first "tuck stitch" operating position, Figure 5 shows a second "dropped stitch" operating position, and Figure 6 shows a third "heel bypass" operating position.

More specifically, a support element 11 is provided around the lower part of the tubular body 5, which is arranged below the needle cylinder 2, and is integral with the support structure of the knitting machine at least with respect to translation along the axis 2a. A cylindrical seat 11a having an axis coinciding with the axis 2a and supporting the tubular body 5 so that it can slide along its own axis crosses the support element 11.

The actuation means 10 is associated with means for controlling the speed of the tubular body 5 while it is moving axially from said inoperative position to said at least one operative position.

In particular, the actuation means 10 comprises motor means 12 adapted to controllably move the tubular body 5 axially from a non-actuated position to at least one actuated position.

Advantageously, the control means is adapted to control the speed of the tubular body 5 during the needle lifting process as it moves axially from the inoperative position to at least one operative position in response to the corresponding rotational speed of the needle cylinder.

According to one possible practical embodiment, the control means is associated with the programming means.

The control means may further be associated with sensor means associated with the needle cylinder 2 and adapted to control the motor means 12 depending on the position of the needle 4.

According to one practical embodiment, the motor means 12 comprises an electric motor having an output shaft 12a constituted by a worm screw which meshes with a block 13 integral with the tubular body 5.

In any case, various coupling means may be provided between the motor means 12 and the tubular body 5 adapted to controllably move the tubular body 5 from an inoperative position to at least one operative position.

The operation of the knitting machine according to the present invention with respect to the movement of the tubular body 5 is as follows.

During normal operation of the knitting machine, the tubular body 5 is in the inoperative position shown in FIG. 3, i.e. the upper end of the tubular body 5 is located at substantially the same level or at a lower level relative to the level of the upper end of the needle cylinder 2.

When an upward action is to be exerted on the product 40 so as to raise it along the needle 4, for example when a loop disposed on the needle 4 as described above is to be transferred from the needle 4 to the gripping member of the transfer member, the motor means 12 can be operated to raise the tubular body 5 a desired amount at a controlled speed.

Figures 4-6 show three different degrees of elevation of the tubular body 5 relative to the needle cylinder 2.

If it is desired to return the tubular body 5 to the inoperative position, it is sufficient to operate the actuating means in the opposite direction.

By way of example, with reference to the type of knitting machine shown in the drawings, at the end of knitting the product 40, all the needles 4 are in the so-called "floating" or "under-sinker" position (Fig. 3) and the tubular body 5 is in its lowest position, i.e. the position used during knitting of the tubular product 40.

This position is virtually universal for all types of knitting machines that perform a method configured to release the closing toe for sewing with a device external to the knitting machine.

At this time, the cam reaches its operating position and begins to raise needle 4, bringing it to the "tuck stitch" position (Figure 4).

In accordance with the present invention, the actuation means 10 is actuated in a controlled manner to raise the tubular body 5 so as to hold the loop in a secure position.

Indeed, if the loop is too low in this process, there is a risk that it will be under the latch, whereas if it is too high, the loop may come out from the head of the respective needle 4.

Once height adjustment is complete at the "tuck stitch" position, another cam is activated, moving needle 4 to the "drop stitch" position (Fig. 5).

During this process, the tubular body 5 continues to move at a controlled speed to maintain the knitted loop in the previously described state.

Once height alignment is complete at the "drop stitch" position, another cam can be actuated to move needle 4 to the "heel bypass" position (Figure 6).

When the "heel bypass" position is in effect, the tubular body 5 is further actuated to move upward at a controlled rate to hold the knitted loop in the previously described position.

When all needles 4 are in the "heel bypass" position, the intervention of the tubular body 5 required to hold the knitted loop in the transfer position is terminated.

Most knitting machines 1 that transfer tubular products perform substantially the same sequence, except possibly for movement to a "heel bypass" position, and the above-described sequence of needle 4 movement is merely an example.

Although the knitting machine according to the invention is specifically conceived to simplify and speed up the operation of automatically transferring a product from a circular knitting machine which produces the product to a machine capable of sewing or looping to close the axial ends of said product, in particular for producing hosiery products, the knitting machine according to the invention may in any case be advantageously used in any situation in which it is necessary to move the product along the needles with which it is engaged.

Indeed, it has been found that the knitting machine according to the invention fully achieves its intended purpose and objective, since by being able to move the product along the axis of the needles with which it is engaged, it simplifies and speeds up the operation for automatically transferring the product from the knitting machine to a transfer member, outside the knitting machine, which is used to perform a sewing looping operation for closing the axial end of the product.

The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims, and all of the details may further be replaced by other technically equivalent elements.

In fact, the materials used and the associated shapes and dimensions can be anything depending on the requirements and current technology, so long as the materials used are suitable for the particular application.

The disclosures in Italian Patent Application No. 102020000006142, from which this application claims priority, are hereby incorporated by reference.

Where technical features described in any claim are followed by reference signs, these reference signs are included solely to enhance the clarity of the claims and therefore do not in any way limit the interpretation of the respective elements identified by such reference signs as examples.

Claims (6)

1. A circular knitting machine, comprising:
The needle cylinder is arranged vertically and is operable by rotational movement about its own axis ,
The skirt of the needle cylinder is provided with a plurality of axial grooves each for receiving a needle ;
a tubular body disposed coaxially within the needle cylinder and adapted to receive the product during formation of the product ;
the tubular body is supported so as to be slidable within the needle cylinder in an axial direction parallel to an axis of the needle cylinder , to move from at least one inoperative position, in which an upper end of the tubular body is disposed at the same level or at a lower level relative to an upper end of the needle cylinder , to at least one operative position, in which an upper end of the tubular body protrudes from an upper end of the needle cylinder ;
an actuating means is provided for commanding said tubular body to move said axially relative to said needle cylinder ;
the circular knitting machine comprising control means associated with the actuation means for controlling a speed of the tubular body while the tubular body is moving axially from the at least one non-actuated position to the at least one actuated position ;
the actuation means comprises motor means adapted to controllably move the tubular body in the axial direction from the at least one inoperative position to the at least one operative position;
The control means is adapted to control a speed of the tubular body during the axial movement of the tubular body from the at least one inoperative position to the at least one operative position in response to a corresponding rotational speed of the needle cylinder . 1. A circular knitting machine, comprising:
The needle cylinder is arranged vertically and is operable by rotational movement about its own axis,
The skirt of the needle cylinder is provided with a plurality of axial grooves each for receiving a needle;
a tubular body disposed coaxially within the needle cylinder and adapted to receive the product during formation of the product;
the tubular body is supported so as to be slidable within the needle cylinder in an axial direction parallel to an axis of the needle cylinder, to move from at least one inoperative position, in which an upper end of the tubular body is disposed at the same level or at a lower level relative to an upper end of the needle cylinder, to at least one operative position, in which an upper end of the tubular body protrudes from an upper end of the needle cylinder;
an actuating means is provided for commanding said tubular body to move said axially relative to said needle cylinder;
the circular knitting machine comprising control means associated with the actuation means for controlling a speed of the tubular body while the tubular body is moving axially from the at least one non-actuated position to the at least one actuated position;
the actuation means comprises motor means adapted to controllably move the tubular body in the axial direction from the at least one inoperative position to the at least one operative position ;
The control means is associated with sensor means associated with the needle cylinder and is adapted to control the motor means in response to the position of the needles. Circular knitting machine according to claim 1 or 2 , wherein the control means is associated with programming means. 4. The circular knitting machine according to claim 1, further comprising means for transferring the tubular product to a station for sewing or looping in order to close one of its axial ends . 5. The circular knitting machine according to claim 1, wherein the at least one operating position comprises a first operating position and a second operating position , the first operating position being a "tuck knit " position and the second operating position being a "drop stitch " position . 6. The circular knitting machine of claim 1, wherein the motor means comprises an electric motor having an output shaft , the output shaft having a worm screw meshing with a block integral with the tubular body .

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